Miniature optical cable for central tube air blowing
By using a coextruded casing structure in the optical cable, the annular area and weight ratio of the polycarbonate layer and polybutylene terephthalate layer are adjusted, and the air blowing distance and efficiency are improved.
Patent Information
- Application Number
- CN202421743167.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-07-22
AI Technical Summary
The miniaturization of optical cables leads to insufficient overall rigidity, affecting the air blowing performance, and cannot meet the air blowing distance and efficiency requirements in application scenarios.
A micro optical cable for air blowing is used for central pipe, which includes optical fiber, coextruded sleeve and sheath. The coextruded sleeve is composed of a polycarbonate layer and a polybutylene terephthalate layer. By adjusting the annular area and weight ratio of these layers, the rigidity and air blowing performance of the optical cable are improved.
It realizes that the rigidity and air blowing distance of the optical cable are improved while meeting the premise of small outer diameter and light weight of the optical cable, and meets the air blowing performance requirements of application scenarios.
Smart Images
Figure CN223006333U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical fiber communication technology, and particularly relates to a miniature optical cable for blowing into a central tube. Background Art
[0002] With the development of optical network services, the shortage of communication pipeline resources is inevitable. Adopting the traditional method for pipeline expansion requires high costs for road excavation and compensation. However, the use of microtube and microcable technology can expand the existing pipeline and maximize the utilization of the original facilities.
[0003] In order to make full use of pipeline resources, the miniaturization of optical cables and high fiber density have become the core demands of customers. However, when the outer diameter of the optical cable is small, the overall rigidity of the optical cable is often insufficient. If the optical cable is too soft, it will greatly affect the blowing performance of the optical cable, and the blowing distance and efficiency will not meet the application scenarios. Summary of the Invention
[0004] Embodiments of this application provide a miniature optical cable for blowing into a central tube to solve the problem in the related technology that in order to make full use of pipeline resources, the miniaturization of the optical cable leads to insufficient overall rigidity of the optical cable and affects the blowing performance of the optical cable.
[0005] In a first aspect, a miniature optical cable for blowing into a central tube is provided, which includes optical fibers. A co-extruded sleeve and a sheath are sequentially arranged outside the optical fibers. The co-extruded sleeve includes a polycarbonate layer and a polybutylene terephthalate layer located outside the polycarbonate layer.
[0006] The area ratio of the annular area corresponding to the cross-section of the polycarbonate layer to the annular area corresponding to the cross-section of the polybutylene terephthalate layer is 1.69 - 4.3.
[0007] In some embodiments, the area ratio is 1.69 - 3.38; or,
[0008] the area ratio is 3.38 - 4.3.
[0009] In some embodiments, the area ratio is 1.69, 3.38 or 4.3.
[0010] In a second aspect, a miniature optical cable for blowing into a central tube is provided, which includes optical fibers. A co-extruded sleeve and a sheath are sequentially arranged outside the optical fibers. The co-extruded sleeve includes a polycarbonate layer and a polybutylene terephthalate layer located outside the polycarbonate layer.
[0011] The weight ratio of the polycarbonate layer to the polybutylene terephthalate layer is 1.56 - 3.96.
[0012] In some embodiments, the weight ratio is 1.56 - 3.11; or,
[0013] The weight ratio is 3.11 to 3.96.
[0014] In some embodiments, the weight ratio is 1.56, 3.11 or 3.96.
[0015] In some embodiments, inside the polycarbonate layer and outside the optical fiber, a fiber paste is filled; the sheath is made of polyethylene or low-smoke halogen-free material; an aramid yarn is provided between the co-extruded sleeve and the sheath.
[0016] In some embodiments, the outer diameter of the sheath is 2.1 - 3.8 mm, and the wall thickness is 0.3 - 0.5 mm;
[0017] The number of optical fiber cores of the optical fiber is 1 - 36 cores; the diameter of the optical fiber is 200 μm or 250 μm.
[0018] In some embodiments, the blowing distance of the central tube blown micro-optical cable under the blowing pressure is greater than 1250 m; the blowing distance is measured under the environment of a temperature range of 5°C - 38°C, a humidity range of 30% - 65%, and a 7 / 4 mm blowing pipeline.
[0019] In some embodiments, the lateral pressure resistance of the central tube blown micro-optical cable is greater than 1000 N, and the lateral pressure resistance is measured under the environment of a temperature range of 5°C - 38°C, a humidity range of 30% - 65%, and a 7 / 4 mm blowing pipeline.
[0020] The beneficial effects brought by the technical solution provided in this application include:
[0021] The embodiment of this application provides a central tube blown micro-optical cable. Since the co-extruded sleeve includes a polycarbonate layer and an outer polybutylene terephthalate layer; the ratio of the annular area corresponding to the cross-section of the polycarbonate layer to the annular area corresponding to the cross-section of the polybutylene terephthalate layer is 1.69 - 4.3; the above structure utilizes the non-crystalline property and relatively high hardness property of polycarbonate, and the property that its density is less than that of polybutylene terephthalate. By changing the size ratio and the proportion of the annular area between the polycarbonate layer and the polybutylene terephthalate layer, the weight ratio between the polycarbonate layer and the polybutylene terephthalate layer is adjusted, and the proportion of the polycarbonate layer is increased. Thus, while reducing the weight of the optical cable, the rigidity of the optical cable can be improved; in addition, the polycarbonate layer has a low shrinkage rate, and the low shrinkage further makes the size of the optical cable smaller compared with the size of the conventional sleeve structure. Finally, the purpose of weight reduction, rigidity improvement, size reduction is achieved, and the blowing distance is increased to improve the blowing performance of the optical cable. Description of the Drawings
[0022] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0023] Figure 1 It is a cross-sectional schematic diagram of a micro-optical cable for central tube air blowing provided by an embodiment of the present application;
[0024] Figure 2 It is a view of the inner and outer diameter dimensions of the polycarbonate layer and the outer polybutylene terephthalate layer provided by an embodiment of the present application.
[0025] In the figure: 1, optical fiber; 2, sheath; 3, polycarbonate layer; 4, polybutylene terephthalate layer; 5, fiber paste; 6, aramid yarn. Detailed implementation manners
[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.
[0027] In order to make full use of pipeline resources, the miniaturization of optical cables and high fiber density have become the core demands of customers. When the outer diameter of the optical cable is small, the overall rigidity is often insufficient. If the optical cable is too soft, it will greatly affect the air blowing performance of the optical cable, and the air blowing distance and efficiency will not meet the application scenarios. How to ensure that the optical cable has sufficient rigidity while meeting the requirements of small outer diameter and light weight of the optical cable to ensure good air blowing performance is the core technical problem of micro air blowing optical cables.
[0028] For the central tube air blowing optical cable, during air blowing construction, the optical cable is suspended in the pipeline by the air flow, and the thrust of the air flow and the thrust of the air blowing equipment enable the optical cable to advance in the air blowing microtube. Only on the basis of having a certain rigidity can the optical cable ensure that it does not undergo serious deformation during pipeline operation.
[0029] How to ensure that the optical cable has sufficient rigidity while meeting the requirements of small outer diameter and light weight of the optical cable to ensure good air blowing performance is the core technical problem of micro air blowing optical cables.
[0030] Generally, the idea of increasing the rigidity of an optical cable is to set a rigid reinforcement in the optical cable, such as GFRP (glass fiber reinforced plastic rod). However, with such a design, the size of the optical cable will surely increase, and the size of the optical cable will not be able to break through the limit. On the other hand, the smaller the size of the optical cable, the relatively lower its rigidity. In the case of insufficient rigidity, the blowing distance will be greatly reduced, and it may even not meet the normal construction requirements.
[0031] In view of the above problems, the embodiments of the present application provide a miniaturized optical cable for blowing through a central tube to solve the problem in the related art that in order to make full use of pipeline resources, the overall rigidity of the optical cable is insufficient due to the miniaturization of the optical cable, which affects the blowing performance of the optical cable.
[0032] Please refer to Figure 1 and Figure 2 , a miniaturized optical cable for blowing through a central tube, which includes an optical fiber 1. An extruded sleeve and a sheath 2 are sequentially arranged outside the optical fiber 1; the extruded sleeve includes a polycarbonate layer 3 and a polybutylene terephthalate layer 4 located outside the polycarbonate layer 3;
[0033] The ratio of the annular area corresponding to the cross-section of the polycarbonate layer 3 to the annular area corresponding to the cross-section of the polybutylene terephthalate layer 4 is 1.69 - 4.3. The above cross-section is a cross-section perpendicular to the axial direction of the optical cable length. The two annuli are located on the same cross-section, and the two annuli are as Figure 2 shown.
[0034] The above structure utilizes the amorphous property and relatively high hardness of polycarbonate PC, as well as the property that its density is less than that of polybutylene terephthalate PBT. By changing the size ratio and the ratio of the annular areas of the polycarbonate layer and the polybutylene terephthalate layer, the weight ratio between the polycarbonate layer and the polybutylene terephthalate layer is adjusted. That is to say, the proportion of the polycarbonate layer is increased, so that while reducing the weight of the optical cable, the rigidity of the optical cable can be improved; in addition, the polycarbonate layer 3 has a low shrinkage rate, and the low shrinkage further makes the size of the optical cable smaller than that of the conventional sleeve structure. Finally, the purposes of weight reduction, rigidity improvement, size reduction are achieved, the blowing distance is increased, and the blowing performance of the optical cable is improved.
[0035] The above extruded sleeve and the optical fiber 1 form an optical unit, and the optical cable of the present application improves the overall rigidity of the optical cable by enhancing the rigidity of the optical unit itself.
[0036] By controlling the ratio of the annular areas of the polycarbonate layer and the polybutylene terephthalate layer, and thus controlling the weight ratio between the polycarbonate layer and the polybutylene terephthalate layer, the rigidity of the optical cable can be adjusted, the weight can be reduced, the overall size of the optical cable can be reduced, so as to achieve the purpose of increasing the blowing distance of the optical cable.
[0037] Of course, for better and more comprehensive definition, the optical cable finally formed by the above structure is further defined, characterized by the final product parameters, and a miniaturized optical cable for blowing into a central tube is proposed, which includes an optical fiber 1, and a co-extruded sleeve and a sheath 2 are sequentially arranged outside the optical fiber 1. The co-extruded sleeve includes a polycarbonate layer 3 and a polybutylene terephthalate layer 4 located outside the polycarbonate layer 3;
[0038] The weight ratio of the polycarbonate layer 3 to the polybutylene terephthalate layer 4 is 1.56 - 3.96.
[0039] In some preferred embodiments, the weight ratio is 1.56 to 3.11; or,
[0040] The area ratio is 3.11 to 3.96.
[0041] In some preferred embodiments, the weight ratio is 1.56, 3.11 or 3.96.
[0042] Through the above description, when determining whether it belongs to the above structure, we can distinguish from the final weight ratio, without measuring the size for calculation, and directly measure the weight. That is to say, as long as the weight ratio of the polycarbonate layer 3 and the polybutylene terephthalate layer 4 of the miniaturized optical cable for blowing into a central tube is within the above range, it is the structure covered by this application.
[0043] Regarding the above control of the proportion of the annular area, the internal principle leading to the weight ratio will be described in detail as follows:
[0044] Therefore, the specific dimensions of the polycarbonate layer 3 and the polybutylene terephthalate layer 4 of the co-extruded sleeve corresponding to the optical cable in this application are defined.
[0045] Regarding the principle in this application that the weight ratio can be adjusted by changing the size, the following detailed description is provided:
[0046] Refer to the appendix Figure 2 And the following calculation formula:
[0047]
[0048] M PC : Weight of the polycarbonate (PC) layer;
[0049] M PBT : Weight of the polybutylene terephthalate layer;
[0050] ρ1: Density of polybutylene terephthalate; the density of polybutylene terephthalate glycol is 1.3l - 1.55 g / cm3; in this application, 1.3 g / cm is taken 3
[0051] ρ2: Density of polycarbonate; the density of polycarbonate is generally 1.20 - 1.22 g / cm 3 , in this application, 1.2 g / cm is taken 3 .
[0052] D1: Outer diameter of the polybutylene terephthalate layer;
[0053] D2: Inner diameter of the polybutylene terephthalate layer. Due to the co - extrusion process, the inner diameter of the polybutylene terephthalate layer is also the outer diameter of the polycarbonate layer;
[0054] D3: Inner diameter of the PC layer; π is the ratio of the circumference of a circle to its diameter. Attach Figure 2 Mark the above - mentioned inner and outer diameters.
[0055] It can be seen from the above formula that it is actually related to the inner and outer diameters of the polybutylene terephthalate layer and the inner and outer diameters of the polycarbonate layer; however, the specific dimensions are difficult to be specifically defined clearly according to different requirements. But as long as its weight ratio is within the range mentioned in this application, it is within the scope covered by this solution.
[0056] Through the above description, changing the dimensions between the polycarbonate layer and the polybutylene terephthalate layer can ultimately achieve the adjustment of the weight ratio.
[0057] Referring to the following table, for the performance of the blowing distance at different weight ratios after actual testing, using co - extruded sleeves in production can effectively improve the blowing performance of the optical cable. As the weight ratio of the PC layer and the polybutylene terephthalate layer increases continuously, the blowing distance increases significantly.
[0058]
[0059] From the above table, we can know that the weight ratio exceeding 1200 m of the blowing distance is 1.56 and above. Therefore, the preferred M PC :M PBT The ratio is 1.56 - 3.96. After conversion, the ratio of the annular areas of the polycarbonate layer and the polybutylene terephthalate layer is 1.69 - 4.3.
[0060] Therefore, the ratio of the annular areas of the polycarbonate layer and the polybutylene terephthalate layer can also be specifically required as: the ratio is 1.69 - 3.38; or, the ratio is 3.38 - 4.3.
[0061] The ratio of the annular areas of the polycarbonate layer and the polybutylene terephthalate layer can also be specifically required as: any one of the ratios 1.69, 3.38 or 4.3.
[0062] In some preferred embodiments, within the polycarbonate layer and outside the optical fiber, fiber grease 5 is filled; the sheath 2 is made of polyethylene or low-smoke halogen-free material. The outer diameter of the sheath 2 is 2.1 - 3.8 mm. The number of optical fiber cores of the optical fiber 1 is 1 - 36 cores; the diameter of the optical fiber 1 is 200 μm or 250 μm. An aramid yarn 6 is provided between the co-extruded sleeve and the sheath 2; the lateral pressure resistance of the central tube blown micro-optical cable is greater than 1000 N.
[0063] Among them, the polybutylene terephthalate layer on the outer layer and the fiber grease inside avoid the long-term contact of the PC layer with moisture in the air, perfectly solving the drawback that the PC layer is prone to hydrolysis for a long time. On the other hand, PC itself does not shrink and has relatively stable dimensions, enabling the optical cable to have good temperature performance even under relatively small design dimensions.
[0064] In some preferred embodiments, the outer diameter range of the optical cable is 2.4 - 2.6 mm, the wall thickness range is 0.3 - 0.5 mm, the weight ratio of the polycarbonate layer to the polybutylene terephthalate layer is preferably 1.56 - 3.96, the number of optical cable cores includes 2 - 12 cores, the optical fiber uses 250 μm, the blowing distance is greater than 1250 m, and the lateral pressure resistance is greater than 1000 N.
[0065] In summary, through the above description, the applicant has realized that by adjusting the weight ratio between the polycarbonate layer and the polybutylene terephthalate layer, the above effects can be achieved. The applicant has conducted several tests and obtained the above structure:
[0066] The blowing distance of the central tube blown micro-optical cable under the blowing pressure is greater than 1250 m; the blowing distance is measured under the environment of a temperature range of 5°C - 38°C, a humidity range of 30% - 65%, and a 7 / 4 mm blowing pipeline.
[0067] The lateral pressure resistance of the central tube blown micro-optical cable is greater than 1000 N, and the lateral pressure resistance is measured under the environment of a temperature range of 5°C - 38°C, a humidity range of 30% - 65%, and a 7 / 4 mm blowing pipeline.
[0068] The optical cable involved in this application uses a co-extruded sleeve and the optical fiber inside as the optical unit. At the same time, when the weight ratio of the PC to the PBT layer in the co-extruded sleeve reaches a certain range, the optical cable can ensure a blowing distance of more than 1200 m.
[0069] In some preferred embodiments, during the actual production process, generally according to the determined M PC :M PBT ratio, and the inner and outer diameters of the polybutylene terephthalate layer, the inner and outer diameters of the polycarbonate layer are determined, so as to finally manufacture and produce a central tube blown micro-optical cable that realizes the purpose of weight reduction, improved rigidity, reduced size, increased blowing distance, and improved blowing performance of the optical cable.
[0070] After production, inspect whether the product meets the above weight ratio requirements. It can be directly measured and calculated by a caliper, or the image can be calculated by taking pictures.
[0071] Advantages of this application:
[0072] The above structure utilizes the amorphous property and relatively high hardness of polycarbonate (PC), as well as the property that its density is less than that of polybutylene terephthalate (PBT). By changing the size ratio of the polycarbonate layer and the polybutylene terephthalate layer and the ratio of the annular areas, the weight ratio between the polycarbonate layer and the polybutylene terephthalate layer is adjusted. That is to say, the proportion of the polycarbonate layer is increased, so that while reducing the weight of the optical cable, the rigidity of the optical cable can be improved; in addition, the shrinkage rate of the polycarbonate layer 3 is low, and the low shrinkage further makes the size of the optical cable smaller than that of the conventional sleeve structure. Finally, the purposes of weight reduction, rigidity improvement, and size reduction are achieved, and the blowing distance is increased to improve the blowing performance of the optical cable.
[0073] In the description of this application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.
[0074] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.
[0075] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A central tube air-blown micro optical cable, comprising an optical fiber (1), a co-extruded sleeve and a sheath (2) being arranged outside the optical fiber (1), characterized in that: The co-extruded sleeve comprises a polycarbonate layer (3) and a polybutylene terephthalate layer (4) located outside the polycarbonate layer (3); The area ratio of the annular area corresponding to the cross section of the polycarbonate layer (3) to the annular area corresponding to the cross section of the polybutylene terephthalate layer (4) is 1.69 to 4.
3.
2. The central tube air-blown micro optical cable according to claim 1, characterized in that: The area ratio is 1.69 to 3.38; or The area ratio is 3.38 to 4.
3.
3. The central tube air-blown micro optical cable according to claim 1, characterized in that: The area ratio is 1.69, 3.38 or 4.
3.
4. A central tube air-blown micro optical cable, comprising an optical fiber (1), the optical fiber (1) being provided with a co-extruded casing and a sheath (2) in sequence, characterized in that: The co-extruded sleeve comprises a polycarbonate layer (3) and a polybutylene terephthalate layer (4) located outside the polycarbonate layer (3); The weight ratio of the polycarbonate layer (3) to the polybutylene terephthalate layer (4) is 1.56-3.
96.
5. The central tube air-blown micro optical cable according to claim 4, characterized in that: The weight ratio is 1.56 to 3.11; or The weight ratio is 3.11 to 3.
96.
6. The central tube air-blown micro optical cable according to claim 4, characterized in that: The weight ratio is 1.56, 3.11 or 3.
96.
7. The central tube air-blown micro optical cable according to claim 1 or 4, characterized in that: The polycarbonate layer is filled with fiber paste (5) outside the optical fiber (1); the sheath (2) is made of polyethylene or low-smoke halogen-free material; and aramid yarn (6) is provided between the co-extruded sleeve and the sheath (2).
8. The central tube air-blown micro optical cable according to claim 1 or 4, characterized in that: The outer diameter of the sheath (2) is 2.1-3.8 mm, and the wall thickness is 0.3-0.5 mm; The optical fiber (1) has 1 to 36 cores; the diameter of the optical fiber (1) is 200 μm or 250 μm.
9. The central tube air-blown micro optical cable according to claim 7, characterized in that: The air blowing distance of the central tube air-blowing micro optical cable under the air blowing pressure is greater than 1250m; the air blowing distance is measured in an environment with a temperature range of 5°C-38°C, a humidity range of 30%-65%, and a 7 / 4mm air blowing pipeline.
10. The central tube air-blown micro optical cable according to claim 7, characterized in that: The lateral pressure resistance of the central tube air-blowing micro optical cable is greater than 1000N, and the lateral pressure resistance is measured in an environment with a temperature range of 5°C-38°C, a humidity range of 30%-65%, and a 7 / 4mm air-blowing pipeline.